Relationships between fibrinogen and insulin resistance

A relationship between plasma fibrinogen levels and insulinemia, as well as the different parameters of the insulin resistance syndrome has been descr ibed. The aim of the present paper was to investigate whether plasma fibrin ogen concentrations were linked to plasma insulin levels or to the degree o f insulin resistance. For this purpose, 62 nondiabetic, nonhypertensive pat ients, 30 men and 32 women, with body mass indexes (BMIs) and ages ranging from 18.6 to 50.2 kg/m(2) and from 19 to 60 years, respectively, were studi ed. Insulin sensitivity was quantified by the minimal model procedure over a 180-min intravenous glucose tolerance test with iterative sampling. Plasm a insulin was determined by radioimmunoassay without cross-reactivity to hu man proinsulin, and fibrinogen by the method of Clauss. Insulin sensitivity ranged from 0.009 to 23.2 min (- 1)(mu U/ml) x 10 (- 4), covering the whol e range of insulin sensitivities. Fibrinogen ranged from 1.70 to 5.07 g/l. There was a significant negative correlation between fibrinogen and insulin sensitivity (r = - 0.76, P < 0.0001) and a positive correlation between fi brinogen and basal insulin (r = 0.56,P < 0.0001). After adjustment for BMI, body fat mass and waist-to-hip ratio, these two relationships remained sig nificant. In addition, a multiple regression analysis was performed to asse ss the independent effect of the following related variables: fibrinogen, i nsulin sensitivity, insulinemia and BMI. Only insulin sensitivity appeared to account for the ability to predict fibrinogen values. Thus, we hypothesi zed it was likely that the state of insulin resistance rather than hyperins ulinemia per se was related to hyperfibrinogenemia. We proposed an interpre tation of these data in connection with some factors like free fatty acids or tumor necrosis factor-alpha, which have been implicated in the pathogene sis of insulin resistance. Nevertheless, prospective and intervention studi es are needed to assess whether there is a simple association or a causal r elationship between insulin resistance and hyperfibrinogenemia. (C) 2000 El sevier Science Ireland Ltd. All rights reserved.